The spine is constituted by superposed vertebrae that are normally in alignment along a vertical axis going from the lumbar vertebrae to the cervical vertebrae, each vertebrae presenting a posterior wall from which there projects a spinous process and two sides having walls from which there project the ribs and/or transverse processes. When the spine of an individual presents abnormal curvature, the vertebrae are inclined relative to one another and/or relative to the vertebral axis. For example, the sides of the vertebrae situated on one side may be moved closer together forming a concave side, whereas the sides of the vertebrae on the other side may be spaced apart from one another and form a convex side.
In order to straighten the spinal column, a spinal stabilization system may be surgically installed along a vertebral segment. In order to keep the vertebrae in a desired relative position, known devices have screws that are inserted in the vertebrae and/or hooks that are inserted along the inside wall of the vertebral canal, and rods that are for interconnecting the screws and/or the hooks.